Pesticidal aerosol compositions



United States Patent 3,303,091 PESTICIDAL AEROSOL COMPOSITIONS Norman G.Mailanrler and Louis M. Sesso, Racine, Wis., assignors to S. C. Johnson& Son, Inc., Racine, Wis. No Drawing. Filed Sept. 10, 1964, Ser. No.395,560 5 Claims. (Cl. 167-39) The present application is aoontinuation-in-part of our US. application, Serial No. 170,241, filedJanuary 31, 1962, noW U.S. Patent 3,159,535.

This invention relates to emulsifier compositions suitable for use withpressurized, self-propellant compositions which produce atomized spacesprays in which the discharged particles remain airborne for asubstantial period of time. More particularly, this invention relates topressurized, self-propellant compositions containing a stable, oil-outemulsion, separate liquid propellant having a specific gravity less thansaid emulsion wherein a portion of said liquid propellant comprises thecontinuous phase of said emulsion, gaseous propellant provided byvolatilization of said liquid propellant and an emulsifier compositioncontaining a polyethoxylated, long-chain fatty acid. When theseself-propellant compositions are combined with various activeingredients, they function effectively as insecticides, fungicides,bactericides, miticides, insect repellants, space deodorants,decongestants and comparable products.

Pesticides,- space deodorants and similar compositions are oftenprovided in aerosol packages from which they are dispensed by sprayinginto the atmosphere. It is obvious that maximum effectiveness of suchcompositions is attained by maintaining the active ingredient airborneas long as possible. Thus, it is apparent that flying insects can bestbe controlled by pesticides in the atmosphere. Therefore, formulators ofcompositions of this nature endeavor to produce sprays in which themajority of the particles are of small diameter since the smaller theparticle, the longer it is likely to remain suspended in air. As ageneral rule, formulators attempt to provide sprays in which 80 percentof the particles are less than 30 microns in diameter, and none are over50 microns in diameter. Obviously, sprays which do not exactly conformto this specification may be more or less suitable as space sprays. Thedefinition is only a technical one and does not necessarily define alleffective space sprays. It is quite apparent, for example, that aparticular insecticide may be so effective that it will control flyinginsects when dispensed in a spray which does not exactly fit thedefinition. The definition does, however, represent a practical goal tobe obtained. Moreover, as will be appreciated by one skilled in the art,these space sprays are substantially different from the coarse sprayssuch as surface sprays which are characterized by a substantial particledrop-out with a corresponding wetting of the surface over which it issprayed. For example, if a space spray is sprayed 12 inches above asurface and the spray pattern is essentially parallel to said surface,in an atmosphere substantially free from the movement of air, saidsurface will be substantially free from wetting directly after sprayingwhereas, a surface spray under similar conditions would producesubstantial wetting of the surface, directly after spraying.

One method of producing sprays having particles which will remainsuspended for the desired period of time is by utilization of atwo-phase system. In this system, the composition sealed in thecontainer contains only two phases, the liquid phase and the gaseousphase. The liquid phase comprises the propellant, the active ingredientsand solvent. The propellant is a normally gaseous liquid, that is, asubstance which is gaseous at standard atmospheric conditions, butliquid under moderate pres- "ice sure, tisobutane anddifluor-odichloromethane, for example. Mixtures of propellants are oftenused. The choice of solvent will depend upon the active solute, the typeof propellant, and end use of the product. Naturally, the liquidingredients must be mutually soluble. The gaseous phase comprises, asthe major ingredient, vapors of the propellant or propellants and maycontain minor amounts of vapors from other ingredients in the liquidphase, for example, kerosene vapors, petroleum ether vapors or naphthavapors, if these are used as solvents. These vapors make a minor andinsignificant contribution to the force which propels the ingredients ofthe container. This force arises from the vaporization of the propellantwhich, as pointed out above, is normally gaseous.

For the utilization of these two-phase systems, and in fact forutilization of any self-propellant ,compo-sition, the container isprovided with a suitable valve mechanism for venting the pressurizedsystem to the atmosphere. The valve is usually hand operated and carriesa dip tube extending into the liquid phase. In its most simple form, thevalve will have two orifices which are substantially opened at the sametime by moving a suitable button. One orifice opens to the dip tube andthe other to the atmosphere. On actuation of the valve, pressure arisingfrom the vaporization of the propellant forces the liquid phase up thedip tube and into the atmosphere. When the propellant reaches theatmosphere, it vaporizes practically instantaneously and with almostexplosive force, thus breaking the liquid stream into a large number ofsmall droplets. As would be expected, with this system, the size of thedroplets is decreased by increasing the amount of the propellant.

A two-phase system such as that described above has a number ofdisadvantages. Perhaps the most important of these, in terms ofgovernment regulations, is the danger of fire or explosion from ventinglarge amounts of hydro carbon propellant into the atmosphere, along withflammable active ingredients or solventstherefor. A secondarydisadvantage is the necessity of utilizing com paratively large amountsof propellants, and using those which are normally quite expensive ifnot flammable.

Effective volatilization of the two-phase system can be considerablyenhanced by providing a valve with a me chanical breakeup outlet. Theprocedure is well known in the art. It merely involves providing theorifice which vents to the atmosphere, hereinafter called the exitorifice, with a mechanical obstruction so that the liquid stream comingfrom the dip tube is broken into a plu rality of smaller streams beforereaching the atmosphere. The mechanical break-up outlet aids somewhat,but does not completely overcome the disadvantages of the twophasesystem referred to above.

An alternative to the two-phase system is the threephase system in whichthe composition in the container consists of three phases: a gaseousphase, a liquid propellant phase and an aqueous phase. As with thetwo-phase system, the gaseous phase comprises vapors of the propellantor propellants as the major component. The liquid propellant phasecomprises as the major component, a normally gaseous hydrocarbon orhalogenated hydrocar: bon or a mixture of these. The aqueous phasecontains the active ingredients and co-solvents, such as alcohol, deemednecessary to dissolve the active ingredients.

In the three-phase system, the propellant may float on the top of theaqueous phase or the reverse. may occur,

depending upon the specific gravity of the two liquid phases. It isundesirable for the propellant to be on the bottom because thisnecessitates frequent shaking or shortening the dip tube so that the diptube does not extend to the lower liquid phase in order to avoid as muchas possible the danger of having only propellant discharged through thevalve. Shortening of the dip tube introduces economic problems since itis not possible to discharge all of the active ingredient. It isapparent, therefore, that in the ideal three-phase system, thepropellant will be the upper layer.

The three-phase system described above is normally not capable ofproducing space sprays. That is, when the system is functioningcorrectly, only the aqueous phase is forced up the dip tube and into theatmosphere. Hence, the explosive force caused by vaporization ofpropellant does not occur and the aqueous phase is emitted as a finestream or a course spray, i.e., .surface spray, rather than as a finespray, i.e., a space spray. I

Two methods have been used heretofore for alleviating this situation;one is frequent shaking, the other is the use of a vapor tap valve. Theformer expedient is far from satisfactory. By shaking, the two liquidphases are mixed so that some propellant in the mixture is forced outofthe dip tube. However, since the liquids are immiscible, they quicklyseparate and the system reverts to its former state. The vapor tap valveis more satisfactory especially when utilized in conjunction with amechanical break-up outlet. w r I The vapor tap valve is well known inthe art. Essentially it is formed by adding to the standard valve amixing chamber interposed between the dip tube and the exit orifice. Themixing chamber is provided with an orifice leading to the vapor phase.Thus, when the vapor tap valveis actuated, some of thevapors from thegaseous phase enter the mixing chamber where they mix with the liquidforced up from the dip tube. The resultant mixture is vented through theexit orifice.

The combination of the vapor tap valve and mechanical break-up outlet,coupled with shaking, markedly decreases the size of the spray droplets.It does not, however, completely solve the problem. I r 7 One of. thedifficulties is that since/some propellant is vented into the mixingchamber, it is necessary to control carefully the amount of propellantpresent in the container so that there is always enough to perform themajor function, that is, the forcing of the aqueous component up the diptube. The problem is even more acute if a mixture of propellants isused. Obviously, the more volatileconstitucut will be selectively bledinto thermixing chamber'so that with continued use the relativeproportion of the two propellants will vary. Furthermore, mechanicalmixing of the propellant vapor and the liquid phase in the mixingchamber of the vapor tap valve will not always accomplish the desiredresult. viscous liquids since these require large amounts of propellantto effect atomization. I tion is best effected by expellingsome liquidpropellant with the aqueous phase.

PRESSURIZED, SELF-PROPELLANT COMPOSITIONS It has now unexpecteldy beendiscovered that space sprays which are suitable as space deodorants,insecticides for flying insects, decongestants and other uses where theactive ingredient must remain airborne for maximum effectiveness, can beobtained by using certain stable oil-out emulsions. This application isconcerned with compositions containing these stable oil-out emulsionsand with certain emulsifiers used to obtain these stable oil-outemulsions. V

More particularly, this application is concerned with pressurized,self-propellant compositions comprising a stable oil-out emulsion,liquid propellant having a specific gravity less than said emulsion andgaseous propellant provided by volatilization of said liquid propellant,wherein at least some of said liquid propellant comprises a portion ofthe continuous phase of said emulsion.

' For'the purposes of the preesnt invention, oil-out emulsioh is definedas an emulsion wherein the outer or con- This is especially true withthe more It is apparent that atomizatinuous phase is oil and the inneror discontinuous phase contains water.

In defining the oil-out emulsion as stable, the accepted definition ofthe term stable is intended, i.e., designed, so as to develop forcesthat restore the original condition when disturbed from a staticcondition and not readily changing in physical state or properties. Forexample, it has been found that a substantial amount of the liquidpropellant is retained as the continuous phase of the oilout emulsionafter prolonged periods of storage. The internal aqueous phase does notcoalesce either upon standing or during agitation. Stable emulsions havebeen observed in certain compositions of the instant invention after 18months of storage. That is, these compositions can be discharged as afine spray from a container, without agitation, after being stored for18 months indicating that the oil-out emulsion containing water, activeingredients, emulsifier and liquid propellant is available fordischargefrom the eductor tube. In addition, it has been found that the stableoil-out emulsions of the present compositions, when combined withseparate liquid propellant wherein the propellant comprises at. least aportion'of the continuous phase of the emulsion, generally do notundergophaseueversal, i.e., coalescence of the dispersed phase eitherbefore or after discharge when subject to conditions which would beexpected to produce same. For example, it has been observed that, ratherthan undergo phase-reversal upon the incorporation of additional Waterinto the dispersed phase, an oil-out emulsion is maintained whichbecomes extremely viscous. Such resistance to phase-reversal has beenobserved where water has comprised up to about percent by weight of thecomposition. At these high concentrations of Water, the compositions ofthe present invention tended to form gels, with a portion of waterseparating from the gel.

The coexistence in a pressurized, self-propellant composition of: (l) aseparate liquid propellant; and (2) astable oil-out emulsion, whereinthe liquid propellant comprises the continuous phase of said emulsion isa novel and unique combination which unexpectedly and unobviouslyprovides uniform and complete discharge of the pressurized compositionafter prolonged periods of storage and/or under a conditionof'continuous discharge; in either case, these results can be obtainedwith little or no necessity for agitation. A separate layer of liquidpropellant is critical to the present invention in that it maintains thestable oil-out emulsion in a charged condition. That is, the separateliquid propellant func: tionsias a'reservoir of propellant, emulsifierand, in some instances, active ingredients forthe continuous phase ofthe stable oil-out emulsion and the gaseous propellant phase. If all theliquid propellant is present as an oil-out emulsion, replenishing thegaseous propellant in the head space in the container which has been'exhaustedthrough the vapor tap orifice, would require escape of liquidpropellant from the emulsion.

The stable oil-out emulsion, separate liquid propellant and gaseouspropellant phases of the composition can be readily mixedby agitation.When the agitation stops, the three phases begin to separate. Thegaseous propellant quickly separates from the liquid phase. Unlike thegaseous phase, separation of the immiscible liquid propellant phase fromthe oil-out emulsion is time dependent. That is, the less dense liquidpropellant rises through the oil-out emulsion phase to form a discretelayer of a separate liquid propellant at the gas/liquid interface. Forexample, shortly after agitation ceases, i.e. after about 30 to 60seconds, a discrete thin layer of propellant can be seen at thegas/liquid. interface. The thickness of the propellant layer increasesas more liquid propellant molecules rise through the oil-out emulsionphase. A substantial increase in the thickness of the propellant layeris seen one hour after shaking. However, one hour after shaking theliquid propellant/ oil-out emulsion interface is not sharply defined. Itis Twenty-four hours after agitation the system is essentially staticwith respect to separation into the three phases. That is, a sharp lineof demarcation defining the liquid propellant/oil-out emulsion interfaceis observed. When observed under conditions free from disturbance afterprolonged periods of storage, the three phases were observed to maintaina similar condition of separation.

When in a stratified condition, the three phases are in equilibrium.That is, the gaseous phase is in equilibrium with the liquid propellantphase. The liquid propellant phase is in equilibrium with the oil-outemulsion. Accordingly, therefore, the separate liquid propellant (thepropellant is present in excess of the amount which can be emulsified)functions as a reservoir of propellant for the gaseous phase and for thecontinuous phase of the oil-out emulsion.

In a preferred embodiment of the invention, the stable oil-out emulsionconsists essentially of water, liquid propellant, active ingredients andemulsifier. In a particularly preferred embodiment of the invention, theliquid propellant is a normally gaseous propellant at atmosphericpressure such as hydrocarbon and halogenated hy drocarbon propellantsand mixtures thereof, and the emulsifier contains anethoxylated,-long-chain, fatty acid such as described below. In anotherembodiment of the invention, the propellant will contain a hydrocarbondiluent such as odorless mineral spirits, kerosene, naphtha, and thelike.

OIL-OUT EMULSIFIERS Only those emulsifiers which produce the stableoil-out emulsions described above can be successfully utilized in thepractice of this invention. These stable oil-out emulsions require thata'substantial portion of the propellant be retained as the continuousphase under essentially all conditions ranging from frequent agitationto remaining static over prolonged durations. In addition, theemulsifier must assure that the requisite rapid expansion of theemulsion takes place upon discharge from the container. The emulsifierssuitable for the present invention manifest very low solubility in waterand good solubility in most non-polar solvents at room temperature.Emulisfiers which have been found especially suitable for the practiceof this invention include mixtures of commercially available oil-outemulsifiers such as various Emcol and Span compositions with certainethoxylated, longchain fatty acids.

These ethoxylated, long-chain fatty acids have been found to beunexpectedly effective for producing stable oil-out emulsions of theinvention. These ethoxylated, long-chain fatty acids are particularlyeffective where the pressurized composition is to be used as a pesticidesuch as an insecticide or the like. Heretofore, it has been difficult toobtain bioassay results in pressurized aqueous base insecticidecompositions comparable to that obtained with pressurized oilbaseinsecticides. In addition, many of the commercially available oil-outemulsifiers are phytotoxic towards plants, which limits their use ininsecticides and similar compositions. Unexpectedly, it has been foundthat the herein described ethoxylated longchain fatty acid esteremulsifiers produce bioassay results with pressurized aqueous-baseinsecticide compositions comparable to those obtained with oil-baseinsecticides. In addition, these emulsifiers are non-phytotoxic at theseconcentrations.

Certain ethoxylated, long-chain fatty acid compounds which are useful asemulsifiers can be defined by the following formula:

and represents the average number of ethoxy groups, i.e., -CH CH -O,present per long-chain, fatty acid Long-chain, fatty acid moiety moiety.Typical long-chain fatty acids which would be included in the aboveformula are: oleic, stearic, palmitic and lauric acid. Ethoxy, in theforegoing formula, represents the organo radical (CH -CH -,-O) derivedfrom ethylene oxide. When X in the above formula appreaches a value ofabout five, the emulsifier tends to become water soluble. Althoughethoxylated, long-chain, fatty acids where the ratio of the fatty acidmoiety to ethoxy groups approaches one are useful, it has been foundthat optimum emulsifying'performance is obtained where the ratio is frombetween about 1:3 to about 1:4 and preferably about 1:3.5. For example,optimum bioassay is obtained with various pesticide compositions of thepresent invention wherein X in th'e'emulsifier has a value of about 3.5.The above formula shall be referred to hereinafter as Formula I.

A particularly preferred emulsifier is the polyoxyethylene glycol esterof stearic acid, i.e., the reaction product represented by the formula:

wherein X has a value of about 3.5. .The value of X represents theaverage number of ethoxy groups in the reaction product per acid moietyand is based on the mole ratio of acid to ethylene oxide reacted. In apreferred embodiment of the invention, one mole of stearic acid and 3.5moles of ethylene oxide are reacted to completion to produce thepolyoxyethylene glycol ester of stearic acid. It is understood, ofcourse, that the reaction product of a long-chain, fatty acid andethylene oxide will comprise molecules wherein the number of ethyleneoxide groups per acid molecule will range from one to greater than five;however, the value of X is based on the mole ratio of the reactants inthe reaction product, where the reaction is continued substantially tocompletion.

As discussed above, the emulsifiers of Formula I are suitable when usedalone in the compositions of the invention, however, in a preferredembodiment, the stable oil-out emulsion of the invention includes acombination of the ethoxylated, long-chain, fatty acids of Formula I andcertain compatible, commercially available oilout emulsifiers. Examplesof the latter include Span 20 (sorbitan monolaurate) and Emcol l4(polyglycerol oleate).

The ratio of the ethoxylated, long-chain, fatty acid emulsifier to thecommercially available oil-out emulsifier can range from about 3:1 toabout 1:1. The commercially available oil-out emulsifiers do not performsatisfactorily for the purposes of the present invention in the absenceof the Formula I emulsifier. However, the com.- bination of theethoxylated long-chain fatty acid emulsifier of Formula I with certaincommercially available oilout emulsifiers does produce unobvious andunexpected results, i.e., improved bioassay, when employed in certainpressurized pecticide compositions of the invention. Unexpectedly, ithas been found that similar results cannot be obtained with combinationsof various commercially available oil-out emulsifiers.

At concentrations of ethoxylated, long-chain, fatty acid emulsifierabove about 3.0 percent by weight, the compositions of the inventionwill contain stable oil-out emula sions. These compositions do providesatisfactory spray characteristics upon discharge; when the activeingredient is a pesticide such as an insecticide, an unsatisfactorybioassay is obtained. However, when the concentration of theethoxylated, long-chain, fatty acid is maintained between about 0.3 andabout 1.5 percent by weight unexpected and unobvious improvements in thespray characteristics and bioassay performance of certain pesticidecompositions are obtained. When the concentration of ethoxylated,long-chain, fatty acid is substantially less than about 0.3 percent byweight, a stable oil-out emulsion as defined above cannot beconsistentlyproduced, and in order to effectively dispense thiscomposition, con- 7 tinuous shaking is required. However, when theconcentration of the ethoxylated, long-chain, fatty acid is at leastabout 0.38 percent by weight and the concentration of the commerciallyavailable oil-out emulsifiers such as Span 80 is 0.24 percent by weight,a satisfactory stable oil-out emulsion is obtainedwhich performseffectively as a pesticide upon discharge. It is thought that thecriticality in the concentration of the Formula I emulsifier is due atleast in partto the rigidity of the emulsion produced. That is, atconcentrations of about 2.0 percent by weight, the Formula I emulsifierproduces a very rigid emulsion which does not tend to break up with theexplosive force desired upon discharge, resulting in less desirablespray patterns and poor bioassays. When less than about 0.3 percent byweightof the Formula I emulsifier is used, the resultant emulsion is notsufficiently rigid and required frequent shaking to discharge some ofthe liquid propellant with the aqueous phase. It is understood that incompositions where spray patterns are not critical that theconcentration of the Formula I type emulsifier can be increased aboveabout 2.0 percent by weight. For example, more than 3.0 percent byweight emulsifier can be used in certain pesticides such as fungicide,miticide, andbactericide formulations. The total emulsifierconcentration in certain of these compositions is often dictated byeconomics. i

Of course, it is understood that the value of X in For mula I and theratio of the Formula I emulsifier to the commercially availableemulsifier will also influence the concentration of emulsifier employed.

Suitable commercially available oil-out emulsifiers are limited to thosecompatible compositions which are effective over prolonged periods oftime, i.e., at least up to 18 months. As discussed above, it is criticalto the present invention that the stable oil-out emulsion of theinstantly claimed compositions be maintained for prolonged periods oftime in order to insure optimum performance. The ethoxylated,long-chain, fatty acid emulsifiers described above have been found toexhibit the requisite effectiveness even after long periods of storage.Certain of the above-discussed commercially available oil-outemulsifiers including the Emcol and Span emulsifiers when in combinationwith the Formula I emulsifier have been found to be satisfactory.

These commercially available oil-out emulsifiers must be compatible withthe Formula I emulsifiers. That is, they should not adversely affect theemulsifying proper ties of the latter compositions. For example, 0.3percent stearyl dimethyl benzyl ammonium chloride (Ammonyx 4002) wascombined with 1.05 percent polyoxyethylene glycol ester of stearic acidwherein X had a value of about 3.5. A water-out emulsion resulted whichproduced a foamy (water-out) spray upon discharge. Due to the poor spraypattern, the composition was not tested for bioassay. 0.4 percentSandrol-ZOOS (a stearic acid derivative from an alkanol amide) wascombined with 1.1 percent of the polyoxyethylene glycol ester of stearicacid. A water-out emulsion resulted. Obviously, neither of the foregoingwould be suitable for the present invention. In the foregoing allpercentages are by weight.

Other substances may be present in the oil-out emulsion includingperfumes, sanitizers, insect repellents and the like. These ingredientswhich may be used alone but are often combined may be generally classedas active ingredients. Typical insecticides include pyrethrins and theirsynergists such as piperonyl butoxide, chlordane, lindane, dieldrin,allethrin, thanite, DDT and others. Certain of these also function asmiticides. Because of unpleasant odors, it is often desirable to maskinsecticides with perfumes. Perfumes include a large class of chemicalmixtures and compounds which excite a pleasing sensation on contact withthe olefactory receptors. These include acids, esters, acetals, ketones,ethers, phenols, amines and others. The selection of a particularperfume or mixture of perfumes for use in a composition of thisinvention will depend upon the effect which it is desired to achieve.Any of a large number of perfumes and mixtures thereof may besuccessfully employed with or without other active ingredients. Amongthe insect repellents which may be successfully utilized in thisinvention, N,N-dimethyl-m-toluamide may be mentioned by way of example.Conventional sanitizers such as propylene glycol or triethylene glycolmay be utilized in limited concentrations. As aforementioned, theidentity of particular active ingredients will depend upon the intendeduse of the finished product as, of course, will the amount of eachactive ingredient.

PROPELLANT The propellants used in the practice of this invention arethe propellants ordinarily utilized in the manufacture of aerosolcompositions which are liquifiable under normal use conditions. Theyinclude hydrocarbon and halogenated hydrocarbon propellants such aspropane, butane, isobutane, isopentane, dichlorodifluoromethane,difluoroethane and tetrafluoroethane. Most halogenated hydrocarbons havea specific gravity which is higher than water. In the practice of thisinvention, these propellants will be diluted with unsubstitutedhydrocarbons such as naphtha to obtain a propellant layer which floatson top of the aqueous layer. Even with a halogenated hydrocarbon, suchas difluoroethane, which is less dense than water but exerts anespecially high vapor pressure, it is sometimes desirable to dilute thepropellant with unsubstituted hydrocarbons such as naphtha. Mixtures ofpropellants will often be employed to decrease the vapor pressure withinthe container to safe limits. Some halogenated propellants exert such ahigh pressure that safety becomes a problem especially at high ambienttemperatures.

The amount of propellant used will depend upon a number of factors, asis well known. With a fairly viscous aqueous phase or when the valveorifices are unusually large, a greater amount of propellant will beemployed than with less viscous aqueous phases and smaller orifices. Itis, of course, desirable to utilize sufficient propellant to spray allof the aqueous phase containing the active ingredient bearing in mindthat some of the propellant will be lost through the vapor tap.Generally speaking, the propellant will amount to from about 20 percentto about 60 percent by weight of the total composition. Smaller amountsmay be employed with aqueous compositions of low viscosity and this maycontribute to lowering the cost of the total composition. Alternatively,with viscous compositions, or if it is desired to eject fairly largeamounts of propellant to assure the attainment of very small droplets,larger amounts of propellant may be used. However, the propellantcontributes significantly to the cost of the composition and it isgenerally preferred to use the minimumv amount which can be effectivelyutilized. In preferred formulations from about 25 percent to about 35percent by weight of propellant based on the weight of the totalcomposition will be used.

It is to be understood that various diluents such as naphtha, odorlessmineral spirits, kerosene and chlorothene (1,1,1-trichloroethane) can beincluded with the propellant. In a preferred embodiment of theinvention, odorless mineral spirits. are combined with Freon 12 toprovide a composition having a Tag open cup flash point above F. (i.e.,122 F.). Similarly, chlorothene can be used as a diluent, however, theresultant propellant composition would be heavier than the emulsion and,accordingly, chlorothene is used in combination with hydrocarbons suchas odorless mineral spirits. The use of propellant diluents isparticularly important where various local and federal fire and shippingregulations are to be complied with. The concentration of propellantdiluent employed Will often be dictated by the particular propellant(s)employed. Generally, however, from about 1 percent to about 25 percentby weight diluent will be used and preferably from about to about 15percent by weight diluent.

VALVING The practice of this invention contemplates the use of a vaportap valve with a mechanical break-up outlet. Both of these are standardand well known in the art. The valve which is sealed in the container toproduce a closed system comprises a premixing chamber and a secondarymixing chamber. The premixing chamber has two orifices. The first is abody orifice in cooperative engagement with a dip tube so that theemulsified liquid coming up the dip tube passes through the orifice andinto the mixing chamber. The second is a vapor tap orifice communicatingwith the vapor phase of the system so that propellant vapor passes intothe premixing chamber where it mixes with the liquid from the dip tube.The mixture thus produced passes then into the secondary mixing chamber.has two orifices, a stem orifice and an exit orifice. The stem orificecommunicates with the premixing chamber so that mixed liquid andpropellant vapors pass readily into it. The exit orifice communicateswith the atmosphere and is constructed with a mechanical obstruction sothat the mixture coming from the secondary mixing chamber is broken upinto a plurality of streams. An exit orifice having a mechanicalobstruction is referred to herein as a mechanical break-up outlet.

When a vapor tap valve is employed it is particularly advantageous tohave separate liquid propellant in the self-propellant composition ofthe invention. For example, this separate propellant, which has aspecific gravity less than the stable oil-out emulsion, provides a readysource of propellant which can be volatilized and thereby maintain thegaseous propellant phase in a charged condition. In contrast, if theentire liquid composition were emulsified, the' liquid propellantrequired to maintain the gaseous propellant phase in a charged conditionwould have to escape, i.e., volatilize, directly from the emulsion. Thislatter condition is usually not satisfactory.

Referring now to the size of the various orifices, the body orifice maybe from about 0.013 to about 0.100 inch in diameter. The stem orifice isfrom about 0.01 to about 0.03 inch in diameter. The vapor tap orifice isfrom about 0.01 to about 0.03 inch in diameter and the mechanicalbreak-up outlet is from about 0.012 to about 0.025 inch in diameter.Certain compositions such as those containing a halogenated hydrocarbonpropellant (Freon 12) and a diluent, such as naphtha, along with activeingredients, emulsifiers and water, do not require a vapor tap valveand, accordingly, conventional valves and stems, i.e., 0.013 inch stemand body, are employed.

Obviously, a fair amount of latitude is possible in the vailving of acontainer of this invention, but some generalizations may be made. Thebody orifice is generally equal to or larger in size than the stemorifice and generally larger than the vapor tap orifice. The mechanicalbreak-up outlet is preferably smaller than the body orifice. Anespecially useful valving system is one in which the body and stemorifices are both 0.025 inch in diameter, the vapor tap orifice 0.013inch in diameter, and the mechanical break-up outlet 0.016 inch indiameter. This preferred valve assembly produces excellent results withrespect to size of the droplets in the spray.

SPRAY PATTERNS The hermetically sealed self-propellant, stable oil-outemulsions of this invention are substantially free of deemulsifiers suchas alcohol and when sprayed through a vapor tap valve having amechanical break-up outlet produce non-flammable space sprays in whichsubstantially all of the component particles remain airborne for anextended period of time, that is, for a sufficient length of time toefficiently accomplish the desired effect. Furthermore, since thesecompositions contain oil-out emulsions The secondary mixing chamberwhich are stable for prolonged periods, i.e., up to 18 months andlonger, space sprays, as defined supra, can be produced even if sprayingis resumed several days after the original shaking and/or undercontinuous spraying conditions. The spray performance of thesecompositions is an extremely important feature of the present invention. Many prior art attempts at space sprays have produced sprays inwhich fine particles exist only during the first few seconds of thespraying. The spray then reverts to one containing a substantialconcentration of larger particles which, because of their larger size,settle almost immediately producing a wet surface in the area sprayed.The difference can be readily appreciated by spraying in front of alight source. It will be seen that sprays produced using a compositionof this invention appear to float in the air, are mist-like, and persistas mist-like sprays even under substantially continuous sprayingconditions, i.e., for up to five minutes or even more. In prior artsprays, there may be an initial surge of spray in which the particlesare similar to the sprays of this invention, however, the spray usuallyquickly reverts to that of a surface spray in which many of theparticles start to settle immediately. This usually occurs in theabsence of continued agitation, over prolonged periods of continuousdischarge, and/or during the discharge of the final portions of theproduct. It is believed that a major factor contributing to theinadequacy of most prior art space sprays is the presence of alcohols inthe aqueous phase,

7 and/or the absence of a stable oil-out emulsion. Generally, in thepresence of alcohol, a known de-emulsifier, emulsions which are formedwhen the container is shaken prior to actuation tend to break up almostimmediately with the result that only limited amounts of propellant aredispensed through the eductor tube along with the aqueous phase and theexplosive force necessary to produce and to continue to produceparticles of a size suflicient to remain airborne is not present. Theemulsions of this invention are sufficiently stable so that propellantis continuously dipsensed through the eductor tube as well as the vaportap to produce airborne particles during spraying cycles of longduration, and also upon discharge without agitation.

The sprays of this invention, despite the presence of large amounts ofpropellant, are essentially non-flammable when tested in accordance withstandard methods. They may, for example, be sprayed into an open 55gall-on drum in which there is a burning taper without evidence of flamepropagation. There is no explosion when the drum is closed. The absenceof alcohol contributes markedly to this effect. Another factor to beconsidered in the matter of flammability is the rate of discharge of thecomposition from the pressurized container. Compositions exemplifiedherein produce discharge rates which are generally less than 0.6 gramper second. Higher rates may sometimes produce positive drum tests,depending upon the nature of the propellant system. The only minimumrate of discharge for the compositions of this invention is dictated bythe practical consideration of dispensing sufficient active material toaccomplish the intended purpose within the time which a person normallyactuates a pressure package. For exampde, if an average person depressesthe actuator button for a period of about ten seconds, there willusually be sufficient pesticide or perfume dispensed in that period tokill the insect or mask the odor.

The following examples are given by way of illustration only and are notintended as limitations of this invention, many apparent variations ofwhich are possible without departing from the spirit and scope thereof.

Example 1 A polyethoxylated, long-chain fatty 'acid of Formula I can beprepared as follows:

648 grams of stearic acid is placed in a reaction .vessel 1. 1 alongwith 1.3 grams of sodium acetate catalyst. The reaction vessel is thenput under a pressure of 3 inches of mercury and placed on a balancealong with a heating bath. The stearic acid catalyst mixture is agitatedand It is apparent from the foregoing that optimum performance can beobtained at total emulsifier concentrations of slightly greater than0.60. Moreover, at a concentration of 0.7 percent olyoxyethylene glycolester of maintained at 160 C. for a period of six (6) hours durstearicacid and 0.24 percent sorbitan monooleate, the ing which time 352 gramsof ethylene oxide are introcomposition was more effective than whentwice the conduced into the vessel at the rate of reaction. The pH ofcentration of each was used. the reaction product upon completion of thereaction is about 8 and is reduced to about 6 by washing the product Cwith an acetic acid solution, thereby removing the sodium 10 acetatecatalyst. Additional insecticide compositions similar to those de- Thetotal weight of the reaction product is approxiscribed in B wereprepared using various commerc ally mately 1,000 grams indicating ayield of almost 100- peravailable emulsifiers rather than the Formula Iemulsifier. ent of a polyethoxylated t i id, The re tion procL Thesecompositions did not produce satisfactory bioassays. uct contains 3.5moles of ethylene oxide per mole of For example, compared to theinsecticide described in B1, stearic acid. these COHl-POSdtlOl'lSperformed as follows:

Knockdown in minutes Emulsifier Spray Pattern Emulsion EthoxylatedStearylcetyl Good Oil-Out -7 -17 -15 alcohol (Siponic E-l).Polyoxyethylene lauryl ether Poor (Foam)- Water-Out (B RH PolyoxethyleneStearyl Amine Coarse. Oil-Out (Ethomeem 18/12). Diglycol cleats/aminepolydo -do glycol.

1 Poor spray and, accordingly, not tested for bioassay.

Example 2 1 Approximately 42 percent of the reaction product ispolyoxyethylene glycol and represents approximately 3.5 ethylene oxidemoieties per acid moiety.

Valving Inches Body orifice 0.025 Stem orifice 0.025 Vapor orifice 0.013Mechanical outlet 0.016

Four similar insecticide compositions were formulated, only theconcentrations of the olyoxyethylene glycol ester of stearic acid andSorbitan monooleate were modified. When tested against house flies inaccordance with the standard Peet Grady procedure, the followingbioassay results were obtained:

Percent Knockdown Comby weight Percent pared to B1 Polyoxyby Weightethylene Sorbitan glycol Monooleate ester of 5 sec. 10 sec. 15 sec.Stearic Acid (131) 1. 4 0.5 (B2) 7 O. 25 6 19 (B3) 0.12 Not Tested 1(B4) 38 0. 24 0 6 4 System requires continuous shaking to provide asuitable spray Other pesticide compositions includeINSECTICIDE-FUNGICIDE D Component: Percent by weight Pyrethrins 0.04Piperonyl butoxide 0.20 Van-cide-89 (Ntrichoromethylthiotetrahydrophthalimide produced by R. T. Vanderbilt)-0.50 Karathane (2.4-dinitro-6-(2-octyl) phenyl crotonate 22.5 percentproduced by Rohm 8: Haas, Philadelphia, Pa. 0.25 Polyoxyethylene glycolester of oleic acid wherein there are about 3.8 moles of ethylene oxideper moleof oleic acid 0.80 Petroleum distillate 0.16

Water 66.05

Isobutane 32.00

100.00 Valving for the foregoing includes:

Inches Body orifice 0.030 Vapor tap orifice 0.013 Stem orifice -a 0.020Mechanical outlet 0.016

FLYING INSECT KILLER Component: Percent by weight Allethrin(DL-2-alkyl-4 hydroxy-3-methyl-2- cyclopentanlone esterified with a cisand trans DL chrysanthe-mu m carboxylic acid, produced by PairfieldChemical Div. Food, Machinery and Chemical Corp. New York,

NY.) 0.40 Thanite T (Isobornyl thiocyanoacetate, produced by HerculesPowder Co., Inc. Wilmington, Delaware) 1.00 Piperonyl butoxide 0.80Sorbitan monolaurate 0.30 Polyoxyethylene glycol ester of oleic acidwherein there are about 3.3 moles of ethylene oxide per mole of oleicacid in the reaction product 0.70

Water 61.80

13 FLYING INSECT KILLER-Continued Isobutane 32.00

Propane 3.00

Valving for the foregoing composition includes:

Inches Body orifice 0.025 Va-por tap orifice 0.015 Ste-m orifice 0.020

Mechanical outlet 0.018

LIVESTOCK SPRAY Component: Percent by weight Allethrin 0.10 RepellentMGK-ll (2,3,4,5-bis (2 butylene) tetrahydrofurfural, manufactured by Mc-Luughlin Go-rmley King Co., Minneapolis, Minn.) 0.50 Repellent MGK326(Di-n-propyl isocinch omerondee manufactured -by McLaughlin Gormley KingCo., Minneapolis, Minn.) 0.50 Polyoxyethylene glycol ester of lauricacid wherein there are about 3.4 moles of ethylene oxide per mole oflauric acid in the reaction product 1.00 Water 69.90

Isobutane 28.00

Valving for the foregoing composition includes:

Inches Body orifice 0.025 Vapor tap orifice 0.020 Stem orifice 0.025

Mechanical outlet 0.016

GARBAGE CAN SPRAY Component: Percent by weight DDT 2.00 Repellent MGK-ll(See Example 2F above) 0.20 Repellent MMGK-326 (See Example 3? above)0.20 Perfume 0.25 Polyoxyethylene glycol ester of palmitic acid whereinthere are 2.0 moles of ethylene oxide per mole of palmitic acid in thereaction product 0.50 Polyg-lycerol oleate 0.20 Water 71.65

Isobutane 22.00

D'ichlorodifiuoromethane 3.00

Valving for the foregoing composition includes:

Inches Body orifice 0.030 Vapor tap orifice 0.020 Stem orifice 0.020

Mechanical outlet 0.020

14- SPACE INSFCTICIDI'] H Component: Percent by weight Pyrethrins 0.23Piperonyl butoxide 2.00 Perfume 0.20

Glycerol monostearate 0.24 Polyoxyethy-lene glycol ester of lauric acidwherein there are 3.7 moles of ethylene oxide per mole of lauric acid inthe reaction product 0.38 Water 65.95

Butane 24.00

Propane 7.00

100.00 Valving for the foregoing composition includes:

Inches Body orifice 0.025 Vapor tap orifice 0.016 Stem orifice 0.025Mechanical outlet 0.020

Example 3 AIR FRESHENERS A Component: Percent by weight Per-fume oil0.60 Polyoxyethylene glycol ester of stearic acid wherein there areabout 3.0 moles of ethylene oxide per mole of stearic acid 1.40 Water68.00 n-Butane 20.00 Dichlorodifluorornethane 5.00

Naphtha 5.00

B Components:

Perfume oil 0.60 Polyoxyethylene glycol ester of oleic acid whereinthere are about 40 moles of ethylene oxide per mole of oleic acid 1.00Propylene glycol stearate 0.35 Water 48.05 Odorless mineral spirits20.00 Dichlorod-ifluoromethane 30.00

The suitable valving for the foregoing air freshener would include:

Inches Body orifice 0.060 Stem orifice 0.030 Vapor tap orifice 0.020Mechanical outlet 0.017

Example 4 B Component:

Menthol -a 0.50 Oil of eucalyptus 0.15

Polyoxyethylene glycol ester or lauric acid wherein there are about 2.5moles of ethylene oxide per mole of lauric acid 2.00 Sorbitan'monopalmitate 0.70 Water 66.65 Isobutane 30.00

Valving for these decolgestats could be similar to that suggested forthe air freshener described in Example 3.

Products similar to the above insecticides, space deodorants,decongestants and the like can be prepared and utilized as miti-cides,bactericides, etc., by replacing the active components, i.e..,insecticides, perfumes and decongestants with suitable pesticidesincluding: miticidcs such as Aramite Z-(p-tertbutylphenoxy)-isopropyl2-chloroethyl sulfite, Chlorbenzide, p-chlorobenzyl p-chlorophenylsulfide, Chlorobenzilate, ethyl 4,4-dichlorobenzilate, Keltbane,1,1'bis(4-chlor0phenyl) 2,2,2-trichloroethanol and Zineb, zincethylenebisdithiocarbamate; nematocides such as Mylone,3,5-dimethyl-1,3,5,,2H-tetrahydrothiadiazine-2-thione,'Tetrachlorothiophene, tetrachlothiophene and Vapam, sodium Nmethyldithiocarbamate; rodentici-des such as Endrin, 1,2,3,4,10,10hexachloro-6 ,7- epoxyl-1,4,4a,5,6,7,8,8a-octahydro-1,4-endo,endo-5,8-dimethanonaphthalene and Warfarin,B-(a-acetoxeylbenzyl)-4-hydroxy coumarin; fungicides such as Brestan,triphenyltin acetate, Captan, N-trichloromethylrnercapto-4-cyclohexene-1,2-dicarboximide, Chloranil, tetrachloro-pbenzoquinone,Chlortetracycline, 7-chloro 4 dimethylamino 1,4,4a,5,5a,6,11.,12aoctahy-dro 3,6,10,12,1221- pentahydroxy 6 methyl 1,11dioxo-2-n'apthacenecarboximide, Folpet, Ntrichloromethylthiophthalimide, Karathane, 2,4-dinitro-6-(2-octl)phenylcrotonate, Mylone, Nabam, disodium ethylenebisdithiocarbamate,Pentachlorophenol, 1, 2,3,4,5-pentachlorophenol, 2,4,5-T, 2,4,5-trichlorophenoxyacetate, and 2,3,6-TBA, 2,3,6-trichlorobenzoic acidand herbicides such as Avadex, 2,3- dichloroallylN,N-diisopropylthiolcarbamate, DNBP, 4,6- dinitro-o-secbutylphenolalkanol amine salts, Maleic hydrazide,1,,2-d-ihydro-pyredazine-3,6-dione, 2,4-D, 2,4-dichlorophenoxyaceticacid and Zytron, o(2,4-dich1orophenyl) o-methyl N-(isopropyl)phosphoramidothioate.

What is claimed is:

1. A pressurized, self-propellant, pesticide composition consistingessentially of:

A. a stable oil-out emulsion;

B. liquid propellant having a specific gravity less than said emulsion;C. gaseous propellant provided by volatilization of said liquidpropellant;

D. pesticide; and

E. from about 0.3 to about 1.5 percent by weight of a polyethoxylatedlong-chain fatty acid emulsifier having the general formula: [long-chainfatty acid moiety] [cthoxy] h, wherein longchain fatty acid moiety] isselected from the group consisting of: oleic, stearic, palmitic, lauricacid and mixtures thereof, and [ethoxy] represents the ethoxy moiety (CHCH O-) and x has a value of from about 1 to about 4 and wherein:

( 1) a portion of said liquid propellant comprises the continuous phaseof said stable oil-out emulsion and the remainder of the liquidpropellant forms a separate liquid layer floating above said stableoil-out emulsion;

(2) said stable oil-out emulsion consists essentially of water,pesiticide, liquid propellant and a portion of said emulsifier; and

(3) said liquid propellant is a normally gaseous propellant selectedfrom the group consisting of hydrocarbon and halogenated hydrocarbonpropellants and mixtures thereof. 7

2. A pressurized, self-propellant, pesticide composition according toclaim 1 wherein the water comprises from about 35 to about 75 percent byWeight of the composition; the propellant comprises from about 25 toabout percent by weight of the composition; and the pesticide comprisesup to about 5 percent by weight of the composition.

3. A pressurized, self-propellant, pesticide composition according toclaim 1 containing a mixture of the polyethoxylated long-chain fattyacid emulsifier with a compatible oil-out emulsifier selected from thegroup consisting of: sorbitan monolaurate, sorbitan monopalmitate,sorbitan mono-leate, polyglce-rol oleate, propylene glycol stearate,glycerol monostearate and mixtures thereof.

4. A pressurized, self-propellant com-position according to claim 1,wherein X has a value of about 3.5.

5. An emulsifier composition according to claim 3 wherein the ratios ofpolyethoxylated long-chain fatty acid to the compatible oil-outemulsifier ranges from between about 3:1 to about 1:1.

References Cited by the Examiner UNITED STATES PATENTS 3,159,535 12/1964Sesso et a1. l6739 JULIAN S. LEVITT, Primary Examiner.

SAM ROSEN, Examiner.

GEORGE A, MENTIS, Assistant Examiner.

1. A PRESSURIZED, SELF-PROPELLANT, PESTICIDE COMPOSITION CONSISTINGESSENTIALLY OF: A. A STABLE OIL-OUT EMULSION; B. LIQUID PROPELLANTHAVING A SPECIFIC GRAVITY LESS THAN SAID EMULSION; C. GASEOUS PROPELLANTPROVIDED BY VOLATILIZATION OF SAID LIQUID PROPELLANT; D. PETICIDE; ANDE. FROM ABOUT 0.3 TO ABOUT 1.5 PERCENT BY WEIGHT OF A POLYETHOYLATEDLONG-CHAIN FATTY ACID EMULSIFIER HAVING THE GENERAL FORMULA: (LONG-CHAINFATTY ACID MOIETY) (ETHOXY)X H, WHEREIN (LONG-CHAIN FATTY ACID MOIETY)IS SELECTED FROM THE GROUP CONSISTING OF: OLEIC, STEARIC, PALMITIC,LAURIC ACID AND MIXTURES THEREOF, AND (ETHOXY) REPRESENTS THE ETHOXYMOIETY (-CH2-CH2-O-) AND X HAS A VALUE OF FROM ABOUT 1 TO ABOUT 4 ANDWHEREIN: (1) A PORTION OF SAID LIQUID PROPELLANT COMPRISES THECONTINUOUS PHASE OF SAID STABLE OIL-OUT EMULSION AND THE REMAINDER OFTHE LIQUID PROPELLANT FORMS A SEPARATE LIQUID LAYER FLOATING ABOVE SAIDSTABLE OIL-OUT EMULSION; (2) SAID STABLE OIL-OUT EMULSION CONSISTSESSENTIALLY OF WATER, PESTICIDE, LIQUID, PROPELLANT AND A PORTION OFSAID EMULSIFIER; AND (3) SAID LIQUID PROPELLANT IS A NORMALLY GASEOUSPROPELLANT SELECTED FROM THE GROUP CONSISTING OF HYDROCARBON ANDHALOGENATED HYDROCARBON PROPELLANTS AND MIXTURES THEREOF.